1. Introduction
This invention pertains to a sprinkler drain and test valve and a method for draining and testing a sprinkler system.
2. Description of the Prior Art
In order to test and drain a fire sprinkler system, an apparatus is used in which a test valve, sight glass, and an orifice providing flow equivalent to the smallest sprinkler orifice in the system are typically located on one conduit in parallel with a second conduit in which an auxiliary drain valve is disposed. Such a system is described in NFPA Pamphlet Number 13 1983 edition at page 13-135, and especially at FIG. A-3-9.1.2. In this system, an indicating-type floor control valve having a supervisory switch is disposed adjacent to a system riser to control feed to a feed main. A water flow switch is provided along the feed main and, subsequent to the water flow switch, a shunt to the prior art drain and test apparatus supplies water from the feed main. Following the shunt, the water can be directed into one of two conduits, the flow through the first being controlled by an inspector's test valve and the flow through the second being controlled by an auxiliary drain valve. When the inspector's test valve is opened, the water passes through the conduit to a sight glass and then through a union having a corrosion-resistant orifice that provides the flow that is equivalent to the smallest sprinkler orifice in the system. While water is flowing through the test conduit, it can be viewed through the sight glass. Alternatively, when it is desired to drain the system, the auxiliary drain valve is opened and water freely flows from the shunt to a drain. In the system described in this reference, the test conduit and the drain conduit rejoin in a single conduit that carries water to the drain.
There are a number of disadvantages in the prior art test and drain apparatus. It is quite complex, consisting of various pipe nipples, fittings, an inspector's test valve, an auxiliary drain valve, a sight glass, and a union joining the test conduit to provide a restricted orifice, and this complexity results in increased costs of installation and operation, and decreased efficiency of use. Thus, there is a need in the art for an improved sprinkler system drain and test apparatus.
Accordingly, it is an object of the present invention to provide a sprinkler system drain and test valve that is easier and more economical to install and operate.
It is a further object of the present invention to provide a sprinkler drain and test valve that requires a minimum amount of space when installed.
It is a further object of the present invention to provide a sprinkler system drain and test valve that, with the operation of a single control, alternatively provides a flow of one sprinkler head, a flow that is unrestricted, or no flow at all through a drain and test conduit.
It is a further object of the present invention to provide a means for observing the flow through a drain and test conduit whether the conduit is carrying a restricted flow, an unrestricted flow, or no flow.
Other objects of the present invention will be apparent from the following detailed description of the preferred embodiments.